[PATCH v8 6/8] cmd: rng: Use a statically allocated array for random bytes
Sughosh Ganu
sughosh.ganu at linaro.org
Fri Jul 22 18:02:07 CEST 2022
Use a statically allocated buffer on stack instead of using malloc for
reading the random bytes. Using a local array is faster than
allocating heap memory on every initiation of the command.
Signed-off-by: Sughosh Ganu <sughosh.ganu at linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
Changes since V7: None
cmd/rng.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/cmd/rng.c b/cmd/rng.c
index 2ddf27545f..81a23964b8 100644
--- a/cmd/rng.c
+++ b/cmd/rng.c
@@ -14,9 +14,9 @@
static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
size_t n;
- struct udevice *dev;
- void *buf;
+ u8 buf[64];
int devnum;
+ struct udevice *dev;
int ret = CMD_RET_SUCCESS;
switch (argc) {
@@ -41,11 +41,10 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
return CMD_RET_FAILURE;
}
- buf = malloc(n);
- if (!buf) {
- printf("Out of memory\n");
- return CMD_RET_FAILURE;
- }
+ if (!n)
+ return 0;
+
+ n = min(n, sizeof(buf));
if (dm_rng_read(dev, buf, n)) {
printf("Reading RNG failed\n");
@@ -54,15 +53,13 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n);
}
- free(buf);
-
return ret;
}
#ifdef CONFIG_SYS_LONGHELP
static char rng_help_text[] =
"[dev [n]]\n"
- " - print n random bytes read from dev\n";
+ " - print n random bytes(max 64) read from dev\n";
#endif
U_BOOT_CMD(
--
2.34.1
More information about the U-Boot
mailing list